Hurricane Katrina demonstrated the need for a comprehensive risk reduction system for the greater New Orleans area. Following Katrina, Congress authorized and funded the construction of the 100-year level risk reduction system, known as the Hurricane and Storm Damage Risk Reduction System (HSDRRS). The HSDRRS includes five parishes (Orleans, Jefferson, St. Bernard, St. Charles, and Plaquemines) and consists of 350 miles of levees and floodwalls; 73 non-Federal pumping stations; 3 canal closure structures with pumps; and 4 gated outlets.

The Greater New Orleans HSDRRS provides the 100-year level of risk reduction against tropical events and related rainfall and storm surges. The $14 billion system includes the construction or improvement of 133 miles of perimeter risk reduction features, such as levees, floodwalls, floodgates, surge barriers, and pump stations. A brief overview will be provided on: 1) the infrastructure improvements; 2) the science behind the storm surge and levee overtopping modeling; 3) impact of the levee system on Hurricane Isaac's storm surge outside the system; 4) possible deficiencies in HSDRRS; and 5) the communities left without protection from HSDRRS.